354 
Tricotylous Races. 
half race occur in the intermediate race also, and as a 
rule all of them in every sowing, provided it is not too 
small. On the other hand, if the half race is cultivated 
on a sufficiently large scale, it will contain all the forms 
of the intermediate race. There is no morphological 
limit between the two, although the physiological one is 
perfectly definite, and in my experiments has never been 
\ 
15 ?0 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 
1 0121 1 6 9 10 7 16 13 13 15 3 1 0. 
Fig. 67. Oenothera hlrtella. Tricotylous 
intermediate race ; curve of hereditary 
capacities of plants of 1896, including 
both atavists and tricotyls. The ca- 
pacities oscillate between 15 and 95%. 
The meaning of the figures is the same 
as in Fig. 66. 
O.t 0.4 0.7 1.0 1.8 1.6 1.9 2.8 1.6 2.8 3.1 3.6 3.7 
26 15 14 10 9 8 5 8 00 Oil. 
Fig. 66. Oenothera rubri- 
nervis. Tricotylous half 
race. Curve of the he- 
reditary capacities of 
the plants of 1894. The 
highest of these was 
3.7%. The upper row 
of figures relates to the 
percentage composition 
in tricotyls, the lower 
to the numbers of 
seed-parents with this 
composition. The ordi- 
nates have the same 
signification as these 
latter figures. 1 
overstepped. The tricotyls of the half race do not lead 
on to the intermediate race, nor do the atavists of this 
race lead on to the half race. The two races are just 
l The percentage figures are calculated, in this experiment, from 
counts made on 300 seedlings from each plant ; but the number of 
ordinates is reduced to one-third. Therefore o.i means, o 0.2; 0.4, 
0.3 0.5 and so on. The tricotylous race-s of Dracocephalum molda- 
I'icum and Penstemon gentianoides gave similar curves. (Harvest 
of 1894). 
